Rotary blower.



L. E. FAGAN.

ROTARY BLOWER.

APPLICATION FILED 33.16, 1909.

Patented Nov. 16, 1909.

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ROTARY BLOWER.

APPLICATION IILBD PEB.16, 1909.

40,587 Patented Nov. 16, 1909.

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LEWIS E. FAGAN, 0F MINNEAPOLIS, MINNESOTA.

ROTARY BLOWER.

caster.

Application filed February 16, 1909.

To all whom it may concern:

Be it known that I, LEWIS E. FAGAN, a citizen of the United States,residing at Minneapolis, in the county of Hennepin and State ofMinnesota, have invented certain new and useful Improvements in RotaryBlowers, of which the following is a specification.

My invention relates to rotary blowers, and particularly to such asembody two intersecting cylindrical casing members one of which containsa fixed core and a driving shaft carrying impellers which revolve in anannular space between the core and casing, and the other of whichcontains a rotating cylindrical drum or idler provided with longitudinalrecesses for receiving the revolving impeller blades during their returnmovements to the suction side of the casing.

My improvement relates to the provision of means whereby at the propertimes the air under pressure carried in the idler recesses as itapproaches the suction side of the blower is enabled to flow throughpassage-ways in the core of the first named casing member to the spacesbetween the impeller blades at the working side, instead of beingcarried to the suction port, thereby effecting a saving of air underpressure and also preventing the noise of its escape at the suctionside.

I attain the objects referred to by the mechanism illustrated in theaccompanying drawings, in which Figure 1 is a transverse section of thepreferred construction of my improved rotary blower taken on the planeof the broken line w-w of Fig. 2 viewed toward the right; Fig. 2 is alongitudinal section of the ma chine on the plane of the broken line ofFig. 1; Fig. 3 is a top view and Fig. 4 shows an end view of one of thecores detached; Fig. 5 is a perspective view of the idler; Fig. 6 is aperspective view of the impeller devices detached from the apparatus;and Fig. 7 shows a portion of the upper casing segment and the plate forfilling the groove in the idler vanes.

In the drawings the casing is shown as consisting of two cylindricalsegments designated respectively 1 and 2, which have their ends closedby heads 3 and at, and these heads are fixed in place and constitute themain supports for the machine. These casing heads 3 and 4: have outwardextensions 5 and 6, respectively, on which are provided Specification ofLetters Patent.

Patented Nov. 16, 1909.

Serial No. 478,186.

the journahboxes 7 and 8 for the drivingshaft 9 and the trunnions 10 ofthe idler. The idler is driven by gear-wheels 11 and 12 connecting oneof its trunnions with the driving-shaft. v

The heads 3 of the lower casing member are provided with stationaryinwardly extending cylindrical hollow cores 13; and axial openings 14are provided in the heads for the driving shaft. The inner ends of thecores are suitably spaced for the operation of the impeller disk, andinward flanges 15 at the core ends provide an ample space 16 to receivethe disk hub. Each of the cores has in its upper surface a groove 17curved in cross-section and extending longitudinally the length of thecore; and in each of these grooves are two longitudinal slots, 18 and19, respectively, and in the lower side of each core is also alongitudinal slot 20. The walls at the outer sides of the slots 18 and19 are extended somewhat within the cores, as shown at 21, and the innersurfaces of these walls or abutment-s 21 are beveled, as shown at 22.The under surface of the portion 23 of the core body intermediate theslots 18 and 19 is made concave.

In the space between the core ends is arranged the disk 24 which isattached to the driving-shaft'by means of its hub To the disk aresecured the impeller blades 26, 27, and 28, extending parallel with theshaft and equally spaced, to operate in the annular space 29 between thecasing and the cores. And the disk also has formed on or secured to itthree valves, 30, 31, and 32, respectively, arranged in radial alinementwith the impeller blades to operatein the chambers of the cores andalternately close and open the slots or ports 18 and 19.

The idler comprises an axial body portion 33 on which are formed twolongitudinal hollow vanes 34, the peripheries of which constitute arcsof a circle, and they are separated by recesses 35 and 36 which arepreferably nearly circular; and it may be formed of two separatesections or be provided with a circumferential groove 37 extending fromthe faces of the vanes to the body or axis The upper portion of thegroove 37 is partially closed by a segmental plate 38 secured to thecasing and having its portion below the axis cut away to permit theimpeller blades to be revolved. This plate serves to steady and guidethe idler in its rotary movements.

The idler is arranged to rotate in the grooves 17 of the cores 13, andthe impeller disk 24 rotates freely in the lower portion of the idlergroove 37. The impeller may be assumed to revolve in the directionindicated by the arrow a and the idler in that indicated by the arrow7). The casing is provided with the usual inlet or suction opening 39 atone side, and discharge opening d0 at the opposite side, so located asto be in communication successively with the spaces between pairs of theimpeller blades and with the idler recesses.

The upper casing member is provided with supplemental chambers orpockets 41 and 42 formed by hollow ribs 43 and 4 1 on the exterior ofthe casing and connected by throats 45 with the chamber within thecasing. These pockets serve as an additional means for saving andreturning air under pressure.

In operation, when the impelleris rotated in the direction indicated bythe arrow (4, and the several devices are in the positions indicated inFig. 1, air is being carried along between the pairs of blades 26 and27, while air is flowing in through the inlet 89 to the space bet-weenthe blades 26 and 28, and air is being discharged from the spaceintervening the blades 27 and 28 against the pressure of the air in theoutlet opening 40. Just before the parts of the machine had rotated tothe positions shown in Fig. 1, the chamber 35 of the idler was incommunication with the outlet port and hence received a charge of airunder pressure which was carried along with the idler until the latterhad reached the position shown and the valve 32 had been moved beyondthe slot 18, when both ports or slots 18 and 19 were opened to the idlerchamber and the air under pressure therein was free to flow there frominto the core chamber and thence through the opening 20 to the spacebetween the impeller blades 26 and 27. Slight further rotation from thepositions shown in Fig. 1 would cause the face of the idler vane 3% toclose the port 18, and the valve carried by the propeller to close theport 19. By this arrangement of devices nearly all of the air underpressure that is not discharged at the outlet is prevented from beingcarried back to the suction side and is saved by being permitted toreturn to the annular space 29 to be again carried by the impeller tothe discharge outlet.

The means for saving and returning air under pressure thus far describedis supplemented by the chambers or pockets 41 and 42. In constructingsuch machines it is usual to have the idlers fit somewhat loosely intheir casing, to avoid the necessity of lubrication, and when soconstructed air under pressure is allowed to enter the intervening spaceat the discharge side and pass around the idlers toward the suctionside. The pockets 41 and 12 are provided to receive the air that thusescapes and store it until the idler makes a partial rotation andpresents one of its recesses 35 or 36 to the throat 43 of the pocket l1or a2 which permits the compressed air stored in such pocket to flowinto the idler recess, in which the .air pressure is lower owing to thefact that such recess was previously in communication with the suctionopening 39, and allows the air so received to be conducted to or towardthe discharge opening.

Having described my invention, what I claim and desire to secure byLetters Patent is- 1. In a rotary blower, a casing, longitudinallygrooved hollow cores therein having ports at opposite sides, impellerblades arranged to revolve in the space between the cores and casing,and valves operated by the impeller for opening and closing core inletports, for the purpose set forth.

2. In a rotary blower, 'a casing, longitudinally grooved hollow corestherein having V ports at opposite sides, impeller blades arranged torevolve in the space between the cores and casing, valves for openingand closing the core inlet ports, and a rotating disk for carrying theimpeller blades and said valves, substantially as set forth.

3. In a rotary blower, a casing, stationary cores therein providing anintermediate annular space and having longitudinal grooves in theirsurfaces, impeller blades arranged to revolve in such annular space,longitudinally recessed idler blades arranged to revolve in said coregrooves, the cores being provided with air ducts extending transverselythrough the core bodies and connecting said surface grooves at the oneside wit-h the annular space at the opposite side, and valves carried bythe impeller for controlling the inlets to said air ducts, substantiallyas set forth.

4. In a rotary blower, a casing, stationary cores therein providing anintermediate annular space and having longitudinal surface grooves andtransverse air ducts connecting such grooves with the annular air spaceat the opposite side of the cores, impeller blades arranged to revolyein said annular space, longitudinally recessed idler blades arranged torevolve in the core grooves, valves for controlling the inlets to saidair ducts, and a rotating disk for operating said impeller blades andvalves, substantially as set forth.

5. In a rotary blower, a casing, stationary cores therein providing anintermediate annular space and having longitudinal surface grooves andtransverse air ducts connecting such grooves with the annular air spaceat the opposite side of the cores, a disk arranged to rotate between thecore ends, im-

peller blades carried by the disk and operating in the annular space,longitudinally recessed idler blades arranged to revolve in the coregrooves, the said air ducts being arranged to permit the passage of airunder pressure from the core grooves to the space between impellerblades at the opposite side, and valves controlled by the impellerrotations for opening and closing the inlets to said air ducts,substantially as set forth.

(3. A rotary blower, comprising a casing, stationary cores thereinhaving longitudinal surface grooves and transverse air ducts connectingsuch grooves with the annular air space at the opposite side of thecores, a disk arranged to rotate between the core ends, impeller bladescarried thereon, longitudinally recessed idler blades arranged torevolve in the core grooves, and valves carried by said disk forcontrolling the inlets to the air ducts, substantially as set forth.

7. A rotary blower comprising a casing formed by intersectingcylindrical segments and heads, cores supported by the heads of one ofthe cylinders and provided with longitudinal grooves along theirsurfaces and transverse air ducts connecting such grooves with theannular air space at the opposite side of the cores, a disk arranged torotate between the adjacent ends of the cores, impeller blades carriedthereon, suitably chambered idlers arranged to rotate in said coregrooves, and valves carried by said disk for controlling the inlets tothe air ducts, substantially as set fOItll.

8. In a rotary blower, a casing, stationary cores therein providing anintermediate annular space and having longitudinal grooves in theirsurfaces, impeller blades arranged to revolve in such annular space, andlongitudinally recessed idler blades arranged to re volve in said coregrooves, the cores being provided with air ducts extending transverselythrough the core bodies and connecting said surface grooves at the oneside with the annular space at the opposite side, and the idler casingbeing provided with pockets arranged to communicate periodically withthe recesses in the idler blades, for the purpose set forth.

9. In a rotary blower, a casing, stationary cores therein providing anintermediate annular space and having longitudinal surface grooves andtransverse air ducts connecting such grooves with the annular air spaceat the opposite side of the cores, impeller blades arranged to revolvein said annular space, longitudinally recessed idler blades arranged torevolve in the core grooves, and hollow ribs formed on the idler casingfor providing storage pockets arranged to communicate periodically withthe recesses in the idler blades, for the purpose set forth.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses this 11th day of February, 1909.

LE'WIS. E. FAGAN.

Vitnesses:

P. H. GUNoKEL, H. A. BOWMAN.

